For a young patient, a visit to Nationwide Children’s Hospital might seem a little better with some colorful fish.

Two hundred of them, including clownfish, puffers and other exotic species, swim among cattails and logs in a new 8-foot aquarium in the lobby of the hospital’s education building.

The renovated area won’t open until late September, but viewers can preview the 420-gallon aquarium tonight when Animal Planet features it on the reality-TV series Tanked.

The stars of the show — native Long Islanders and brothers-in-law Wayde King and Brett Raymer — installed the aquarium at the hospital during three days last month.

Their Las Vegas-based Acrylic Tank Manufacturing has designed and built more than 10,000 aquariums during the past 16 years.

Through four seasons of the series, which they pitched to the cable network, King and Raymer have become known for one-of-a-kind custom creations that can carry six-figure price tags. The cost of a 75,000-gallon tank for a Dallas megachurch: $4 million.

This season, they created a doughnut-shaped tank for Dunkin’ Donuts and an aquarium housed in the front window of a recreational vehicle for a dealership. They wowed Miami Heat player Dwyane Wade by creating a tank for the launch party for his new shoe, Sting Ray — with stingrays swimming around the sneakers.

The show has led to daily tours of company headquarters and the two stars being stopped by fans wherever they go (including the hospital).

“I’ve taken more photographs and signed more autographs in probably one year than my whole life,” Raymer said.

The aquarium for Children’s stemmed from an existing relationship between the network and Nationwide Insurance, which purchases advertising during Tanked and other Animal Planet shows.

As part of Nationwide’s purchase, Animal Planet offered a custom tank to Nationwide, which then donated the opportunity (estimated at $60,000) to its partner hospital.

Patients had noticed the absence of a small aquarium in the lobby, which was removed during renovation. So many asked about “Nemo” that the hospital displayed a sign: The fish are on vacation.

The new tank, said Dr. Steve Allen, Children’s CEO, fits perfectly with the nature theme of the hospital’s decor. The lobby area had already been named “The Pond.”

“What’s really important to us is that the environment conveys a sense of hope and courage and strength,” Allen said. Allen and Matt Jauchius, chief marketing officer for Nationwide Insurance, are featured in the episode as the “clients” who discuss their visions for the tank.

At the hospital, suspenseful music plays as construction workers right the 2,300-pound tank.

To film the episode’s “reveal,” families of patients joined employees from Nationwide and the hospital behind the construction wall to see the debut of the tank.

The “reality” wasn’t fully real, Jauchius acknowledged, but his enthusiasm was genuine.

“It was easy to be happy and express excitement about it,” he said, “because it’s pretty spectacular.”